Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science


Many South Dakota farmers depend upon the pig enterprise for a portion of their yearly income. According to the South Dakota Crop and Livestock Reporting Service, approximately 19 per cent of the cash farm income of South Dakota is obtained from the marketing of hogs. The successful swine producer’s primary objective is to receive the greatest possible financial return for his investment and labor. In order to accomplish this aim, it is often desirable to feed a ration which produces as fast a rate of gain as possible without sacrificing feed efficiency or carcass quality. The growth response obtained by feeding antibiotics to pigs was first realized in the summer of 1949. Since that time, many experiments have been performed with antibiotic supplementation of various swine rations. The work reported herein is a portion of a project conducted by the Animal Husbandry Department at South Dakota State College in an effort to determine the value of antibiotic supplementation in pig rations. The objectives of this study were to determine the effects of discontinuing antibiotic supplementation during the growing-fattening period, and the value of combining more than one antibiotic in rations for growing-fattening pigs. Rate of gain, feed efficiency, and carcass quality were used in determining the value of the various treatments.

Library of Congress Subject Headings

Swine -- Feeding and feeds


Includes bibliographical references (pages 49-52)



Number of Pages



South Dakota State University


No Copyright - Non-Commercial Use Only